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External Thermal Insulation Composite Systems (ETICS) have been extensively used for either new constructions or building facades retrofitting in the last decades. These systems can provide improved thermal performance to the building envelope. However, their long-term durability remains a pervasive concern, with some systems presenting relevant anomalies after few years from their application. The durability assessment of ETICS is defined by the EAD 040083-00-0404 guideline, which stated an accelerated ageing procedure based on the hygrothermal and freeze-thaw behaviour. Nevertheless, further important environmental urban conditions, such as UV radiation and atmospheric pollutants, as well as bio-susceptibility, are not envisaged in the guideline. This paper presents the results of an experimental campaign with the aim of evaluating the durability of the rendering system of several commercially available ETICS exposed to an innovative accelerated ageing procedure, which consists of hygrothermal cycles, UV radiation and air pollutants (SO2) exposure. Physical and chemical-morphological tests were carried out prior and after each ageing cycle in order to evaluate the durability of ETICS. Biological susceptibility to moulds was also assessed. The experimental results showed that both surface hardness and surface gloss decreased after the combined effect of the hygrothermal, UV, and SO2 ageing cycles, whereas an increase of surface roughness was observed. Substantial colour change for all systems after the ageing procedure was observed, confirming aesthetic alteration. Traces of biological growth were detected on the systems after ageing and the contact angle decreased after the hygrothermal cycles, indicating a lower surface hydrophobicity of the systems.
João L. Parracha; Giovanni Borsoi; Rosário Veiga; Inês Flores-Colen; Lina Nunes; Ana R. Garcia; Laura M. Ilharco; Amélia Dionísio; Paulina Faria. Effects of hygrothermal, UV and SO2 accelerated ageing on the durability of ETICS in urban environments. Building and Environment 2021, 204, 108151 .
AMA StyleJoão L. Parracha, Giovanni Borsoi, Rosário Veiga, Inês Flores-Colen, Lina Nunes, Ana R. Garcia, Laura M. Ilharco, Amélia Dionísio, Paulina Faria. Effects of hygrothermal, UV and SO2 accelerated ageing on the durability of ETICS in urban environments. Building and Environment. 2021; 204 ():108151.
Chicago/Turabian StyleJoão L. Parracha; Giovanni Borsoi; Rosário Veiga; Inês Flores-Colen; Lina Nunes; Ana R. Garcia; Laura M. Ilharco; Amélia Dionísio; Paulina Faria. 2021. "Effects of hygrothermal, UV and SO2 accelerated ageing on the durability of ETICS in urban environments." Building and Environment 204, no. : 108151.
This article evaluates the relevant properties of cement-bonded particleboards (CBPB) made with a portion of maritime pine (Pinus pinaster) particles replaced with an agricultural waste, banana pseudostem (Musa sp.). The industrial production of CBPB was simulated in the laboratory based on a reference composition defined by a manufacturing company. Test specimens were produced assuming 0%, 25%, 50% and 75% partial replacement of wood particles with banana pseudostem fibres. Some physical properties (bulk density, thermal conductivity, and dimensional stability) and the mould susceptibility of the different variables were assessed. Results show that the thermal conductivity of the boards increased with the banana fibre proportion and ranged between 0.233 W/(m.K) and 0.279 W/(m.K). The bulk density values generally increased with the banana fibre proportion and ranged between 1754–1995 kg/m3, being the highest value obtained for B50 (equal weight proportion of wood particles and banana fibres). Specimens with a higher percentage of banana fibres have reduced thickness resulting from swelling, ranging between 0.38% and 0.11% (for 0% and 75% of banana fibres, respectively). CBPBs with unsanded surfaces seem to be unsusceptible to mould development, whereas those with sanded surfaces, simulating wearing, show some bio-susceptibility. Mould development increases with the proportion of banana fibre. The results highlight the need for regular maintenance of the particleboards, thus avoiding surface wear over time and resulting in the exposure of the wood particles and/or banana fibres to the outside environment.
Lina Nunes; Eleonora Cintura; João Parracha; Bruno Fernandes; Vitor Silva; Paulina Faria. Cement-Bonded Particleboards with Banana Pseudostem Waste: Physical Performance and Bio-Susceptibility. Infrastructures 2021, 6, 86 .
AMA StyleLina Nunes, Eleonora Cintura, João Parracha, Bruno Fernandes, Vitor Silva, Paulina Faria. Cement-Bonded Particleboards with Banana Pseudostem Waste: Physical Performance and Bio-Susceptibility. Infrastructures. 2021; 6 (6):86.
Chicago/Turabian StyleLina Nunes; Eleonora Cintura; João Parracha; Bruno Fernandes; Vitor Silva; Paulina Faria. 2021. "Cement-Bonded Particleboards with Banana Pseudostem Waste: Physical Performance and Bio-Susceptibility." Infrastructures 6, no. 6: 86.
External Thermal Insulation Composite Systems (ETICS) are constructive solutions widely used to increase the thermal insulation in new and retrofitted buildings. However, these systems can present several anomalies due to their constant exposure to weathering agents and anthropic factors. Water is generally the major cause of degradation. Thus, the application of water-repellent products can minimize the appearance of anomalies and increase the durability of the systems. In this paper, acrylic-based and siloxane-based hydrophobic products were applied to ETICS, with the aim of assessing the compatibility, effectiveness, and durability of these products. The moisture transport properties and mould susceptibility were assessed through laboratory tests on untreated and treated specimens. The durability of the hydrophobic treatments was also evaluated through artificial aging tests (heat-cold and freeze-thaw cycles). Results show that the protection products generally decreased water absorption, slightly decreased the drying rate, and presented adequate water vapor permeability. After aging, the products still had reasonable effectiveness and, with one exception, improved the water vapor diffusion of the systems. Additionally, ETICS underwent an alteration in the finishing coat (possible modification of the porosity) due to the aging cycles. No clear linear correlation was found between the contact angle values and water absorption results, evidencing the influence of other factors related to the composition of the water-repellent products.
Renata Roncon; Giovanni Borsoi; João Parracha; Inês Flores-Colen; Rosário Veiga; Lina Nunes. Impact of Water-Repellent Products on the Moisture Transport Properties and Mould Susceptibility of External Thermal Insulation Composite Systems. Coatings 2021, 11, 554 .
AMA StyleRenata Roncon, Giovanni Borsoi, João Parracha, Inês Flores-Colen, Rosário Veiga, Lina Nunes. Impact of Water-Repellent Products on the Moisture Transport Properties and Mould Susceptibility of External Thermal Insulation Composite Systems. Coatings. 2021; 11 (5):554.
Chicago/Turabian StyleRenata Roncon; Giovanni Borsoi; João Parracha; Inês Flores-Colen; Rosário Veiga; Lina Nunes. 2021. "Impact of Water-Repellent Products on the Moisture Transport Properties and Mould Susceptibility of External Thermal Insulation Composite Systems." Coatings 11, no. 5: 554.
The present study aims at evaluating the impact of anobiid damage on pine timber elements. Anobiid attack produces a diffuse damage of the elements with a set of tunnels in random directions and sizes, thus confusing quantification. Therefore, a method was developed based on X-ray micro-computed tomography (μ-XCT) to obtain, for naturally infested timber samples, an empirical correlation between lost material percentage (consumed by beetles) and timber apparent density (original, before degradation—OTD and residual, after degradation—RTD). The quantified density loss can then be used in further assessment of the structure. The results of the tests performed showed high correlation between original apparent density and lost material percentage (r2 = 0.60) and between residual apparent density and lost material percentage (r2 = 0.83), which confirms μ-XCT as a valuable tool to the required quantification. The loss of density results can be further applied on the definition of an assessment method for the evaluation of the residual strength of anobiids infested timber, thus contributing to reducing unnecessary replacement. The optimized procedure of the μ-XCT study for infested Maritime pine (Pinus pinaster) is presented and discussed in this article.
João Parracha; Manuel Pereira; António Maurício; Paulina Faria; Daniel Lima; Marina Tenório; Lina Nunes. Assessment of the Density Loss in Anobiid Infested Pine Using X-ray Micro-Computed Tomography. Buildings 2021, 11, 173 .
AMA StyleJoão Parracha, Manuel Pereira, António Maurício, Paulina Faria, Daniel Lima, Marina Tenório, Lina Nunes. Assessment of the Density Loss in Anobiid Infested Pine Using X-ray Micro-Computed Tomography. Buildings. 2021; 11 (4):173.
Chicago/Turabian StyleJoão Parracha; Manuel Pereira; António Maurício; Paulina Faria; Daniel Lima; Marina Tenório; Lina Nunes. 2021. "Assessment of the Density Loss in Anobiid Infested Pine Using X-ray Micro-Computed Tomography." Buildings 11, no. 4: 173.
Biotechnologies mainly based on precipitation of chemical compounds produced by microbial metabolism can be used as biotreatment or bioformulation of construction materials. Bioformulation of cement-based materials has been a common research practice, though its application to earthen-based building materials is still limited. Although earth mortars are vulnerable to water damage, they are nowadays often used as plasters on new constructions but also for the retrofitting of existent buildings. Their reversibility and compatibility with old substrates make them also interesting for conservation interventions, namely when applied to protect archaeological structures as sacrificial renders. In this study, an innovative bioproduct based on cellular extracts of Escherichia coli, cultured in Lysogeny broth (LB) medium and supplemented with iron, was developed and used as a component for earth mortars’ bioformulation. The Escherichia coli strain used is classified as not hazardous. An additional earth mortar bioformulated with LB medium as mixing liquid was also tested to assess the influence of the culture medium. The iron supplement was chosen to infer about iron oxide biomineral formation, a less toxic mineral than calcite, since no toxic by-products are produced, and iron oxide minerals have a longer lifetime when compared with calcite crystals. Bioformulated mortars presented a very distinct porous structure, with a significant decrease on mechanical properties. Nevertheless, they also showed a decrease on thermal conductivity, a slight consolidative effect, and a significant decrease on vulnerability towards water. Apart from the possible use as mortar air entraining agents, the obtained results show the interest on further studies on the use of nontoxic iron-based bioproducts for earthen mortars optimization.
J.L. Parracha; A.S. Pereira; R. Velez da Silva; V. Silva; P. Faria. Effect of innovative bioproducts on the performance of bioformulated earthen plasters. Construction and Building Materials 2021, 277, 122261 .
AMA StyleJ.L. Parracha, A.S. Pereira, R. Velez da Silva, V. Silva, P. Faria. Effect of innovative bioproducts on the performance of bioformulated earthen plasters. Construction and Building Materials. 2021; 277 ():122261.
Chicago/Turabian StyleJ.L. Parracha; A.S. Pereira; R. Velez da Silva; V. Silva; P. Faria. 2021. "Effect of innovative bioproducts on the performance of bioformulated earthen plasters." Construction and Building Materials 277, no. : 122261.
In Portugal, rammed earth monolithic walls and adobe masonry were, for several centuries, important construction techniques for dwellings. The frequent unnecessary demolition of these buildings, mainly due to lack of information related to them, lack or inadequate maintenance interventions, and advanced state of degradation, has been leading to great cultural and material loss. To preserve this vernacular built heritage and all the technological knowledge related to it, it is fundamental to understand the constructive technologies. Several earthen buildings from Leiria region were mapped and inspected, and two of them were taken as case studies. This architectural survey allowed studying their construction specificities, main building pathology, and thus contributing to Leiria's vernacular earthen buildings efficient preservation and use.
João Luís Parracha; José Lima; Maria Teresa Freire; Micael Ferreira; Paulina Faria. Vernacular earthen buildings from Leiria, Portugal – Architectural survey towards their conservation and retrofitting. Journal of Building Engineering 2020, 35, 102115 .
AMA StyleJoão Luís Parracha, José Lima, Maria Teresa Freire, Micael Ferreira, Paulina Faria. Vernacular earthen buildings from Leiria, Portugal – Architectural survey towards their conservation and retrofitting. Journal of Building Engineering. 2020; 35 ():102115.
Chicago/Turabian StyleJoão Luís Parracha; José Lima; Maria Teresa Freire; Micael Ferreira; Paulina Faria. 2020. "Vernacular earthen buildings from Leiria, Portugal – Architectural survey towards their conservation and retrofitting." Journal of Building Engineering 35, no. : 102115.
The use of External Thermal Insulation Composite Systems (ETICS) significantly increased in the last decades due to their enhanced thermal properties, low installation cost and ease of application, not only in new constructions but also for thermal retrofitting of building facades. These multilayer rendering systems are constantly exposed to weathering agents and anthropic factors which can lead to physical-mechanical and aesthetical anomalies and thus affect their durability. However, possible synergetic effects among these agents are often neglected by international technical documents on the evaluation of the effectiveness and durability of ETICS. With the aim of filling this gap, moisture transport properties (capillary water absorption, water vapor permeability, water absorption under low pressure, and drying kinetics), thermal conductivity, mould susceptibility and surface properties (color, gloss, and roughness) of twelve commercially available ETICS were assessed and discussed. Possible links between these factors were analyzed and ETICS performance parameters were defined. Results demonstrate that a deeper knowledge of the correlation among ETICS properties can effectively contribute to the evaluation of the efficiency and long-term durability of these systems.
J.L. Parracha; G. Borsoi; I. Flores-Colen; R. Veiga; L. Nunes; A. Dionísio; M. Glória Gomes; P. Faria. Performance parameters of ETICS: Correlating water resistance, bio-susceptibility and surface properties. Construction and Building Materials 2020, 272, 121956 .
AMA StyleJ.L. Parracha, G. Borsoi, I. Flores-Colen, R. Veiga, L. Nunes, A. Dionísio, M. Glória Gomes, P. Faria. Performance parameters of ETICS: Correlating water resistance, bio-susceptibility and surface properties. Construction and Building Materials. 2020; 272 ():121956.
Chicago/Turabian StyleJ.L. Parracha; G. Borsoi; I. Flores-Colen; R. Veiga; L. Nunes; A. Dionísio; M. Glória Gomes; P. Faria. 2020. "Performance parameters of ETICS: Correlating water resistance, bio-susceptibility and surface properties." Construction and Building Materials 272, no. : 121956.
João Luís Parracha; António Santos Silva; Mafalda Cotrim; Paulina Faria. Mineralogical and microstructural characterisation of rammed earth and earthen mortars from 12th century Paderne Castle. Journal of Cultural Heritage 2020, 42, 226 -239.
AMA StyleJoão Luís Parracha, António Santos Silva, Mafalda Cotrim, Paulina Faria. Mineralogical and microstructural characterisation of rammed earth and earthen mortars from 12th century Paderne Castle. Journal of Cultural Heritage. 2020; 42 ():226-239.
Chicago/Turabian StyleJoão Luís Parracha; António Santos Silva; Mafalda Cotrim; Paulina Faria. 2020. "Mineralogical and microstructural characterisation of rammed earth and earthen mortars from 12th century Paderne Castle." Journal of Cultural Heritage 42, no. : 226-239.
João Luís Parracha; Alice S. Pereira; Ricardo Velez da Silva; Nídia Almeida; Paulina Faria. Efficacy of iron-based bioproducts as surface biotreatment for earth-based plastering mortars. Journal of Cleaner Production 2019, 237, 1 .
AMA StyleJoão Luís Parracha, Alice S. Pereira, Ricardo Velez da Silva, Nídia Almeida, Paulina Faria. Efficacy of iron-based bioproducts as surface biotreatment for earth-based plastering mortars. Journal of Cleaner Production. 2019; 237 ():1.
Chicago/Turabian StyleJoão Luís Parracha; Alice S. Pereira; Ricardo Velez da Silva; Nídia Almeida; Paulina Faria. 2019. "Efficacy of iron-based bioproducts as surface biotreatment for earth-based plastering mortars." Journal of Cleaner Production 237, no. : 1.
In Portugal, a large number of vernacular earthen buildings present an advanced state of degradation. These buildings comprise historical, technological, architectonic, cultural and social recognized values and, therefore, efficient interventions are needed for their conservation. The knowledge of the properties that the materials used in their construction show nowadays is one of the bases to support future interventions. Unstabilized earthen samples were collected from the walls of six earthen buildings located in the region of Leiria, Portugal, built with rammed earth and/or adobe masonry. The samples were characterized by particle size distribution and through XRD, density, capillary absorption, drying, dry abrasion, compressive and tensile flexural strength. Mechanical results of rammed earth were lower than adobe’s, contrary to what was commonly found in other studies, and capillary coefficients of adobe were comparable to lime-stabilized adobe from other regions. A surface protection by compatible renders, respectively, earthen-based and air lime-based, is strongly encouraged to extend the walls durability. Although based on a short sampling, this data gives initial support to future compatible, effective and reversible interventions in Leiria vernacular earthen buildings, contributing to the preservation of this earth-built heritage.
João Luís Parracha; José Lima; Maria Teresa Freire; Micael Ferreira; Paulina Faria. Vernacular Earthen Buildings from Leiria, Portugal – Material Characterization. International Journal of Architectural Heritage 2019, 1 -16.
AMA StyleJoão Luís Parracha, José Lima, Maria Teresa Freire, Micael Ferreira, Paulina Faria. Vernacular Earthen Buildings from Leiria, Portugal – Material Characterization. International Journal of Architectural Heritage. 2019; ():1-16.
Chicago/Turabian StyleJoão Luís Parracha; José Lima; Maria Teresa Freire; Micael Ferreira; Paulina Faria. 2019. "Vernacular Earthen Buildings from Leiria, Portugal – Material Characterization." International Journal of Architectural Heritage , no. : 1-16.
In this article, an assessment method to estimate the residual strength of pine structural elements degraded by anobiids is presented. This novel method was developed in the laboratory to be used in situ and is based on the strength required to withdraw a screw on the surface of degraded timber. Samples of degraded maritime pine (Pinus pinaster Ait.) were submitted to micro-computed tomography (μ-XCT) to quantify density loss. This parameter is highly correlated with mechanical properties thus central for the assessment of timber structural capacity. Density loss values have been correlated with both screw withdrawal force and shear parallel to the grain strength showing significant relationships between these parameters. Using these correlations, the density loss of a degraded element and its shear strength parallel to the grain via the screw withdrawal force can be estimated enabling a valid quantitative assessment of the timber elements residual strength and, therefore, contributing to reduce unnecessary replacement, to boost eco-efficient interventions and to provide foundations required to perform experimental modelling tests.
João L. Parracha; Manuel Pereira; António Maurício; José Saporiti Machado; Paulina Faria; Lina Nunes. A semi-destructive assessment method to estimate the residual strength of maritime pine structural elements degraded by anobiids. Materials and Structures 2019, 52, 54 .
AMA StyleJoão L. Parracha, Manuel Pereira, António Maurício, José Saporiti Machado, Paulina Faria, Lina Nunes. A semi-destructive assessment method to estimate the residual strength of maritime pine structural elements degraded by anobiids. Materials and Structures. 2019; 52 (3):54.
Chicago/Turabian StyleJoão L. Parracha; Manuel Pereira; António Maurício; José Saporiti Machado; Paulina Faria; Lina Nunes. 2019. "A semi-destructive assessment method to estimate the residual strength of maritime pine structural elements degraded by anobiids." Materials and Structures 52, no. 3: 54.
The safety assessment of old timber structures is an important issue, due to the long-term behaviour of wood and the structural complexity found in some older constructions. If the structure is degraded due to the action of wood-boring insects, the complexity of the analysis increases. The objective of this work was to evaluate the impact of anobiid beetles’ attack on old timber structures. One major difficulty concerns the assessment of the effective strength of timber cross sections with anobiid damage. This happens because beetles’ attack produces a diffuse damage, with a set of tunnels in random directions.Compression parallel to the grain and screw withdrawal tests have been made in pine naturally degraded by anobiids (natural samples – NS) and in pine with artificially bored galleries (artificial samples – AS). 216 samples were tested (97 to screw withdrawal and 119 to compression). The original density of NS is unknown. For AS, 0.7% and 1.4% of lost material was simulated. Screw withdrawal and compression force values were related with density for AS (𝑟2 = 0.52 for compression; 𝑟2 = 0.56 for screw withdrawal). The results show a significant variation between the average results obtained both to the compression (42.9 MPa – AS; 27.2 MPa – NS) and to the pull- out (3.4 KN – AS; 2.2 KN – NS).Although there was an attempt to simulate the degradation by woodworm with the AS, with known density, the test results were significantly different from those obtained for the NS, where the percentage of lost material is unknown, as well as initial density. Thus, knowledge of residual timber density seems to be paramount to know the level of deterioration and the real impact of this on a structure. Further developments on this issue are ongoing.
Lina Nunes; João Luís Parracha; Paulina Faria; Pedro Palma; António Maurício; Manuel Pereira. Towards an assessment tool of anobiid damage of pine timber structures. IABSE Symposium, Guimarães 2019: Towards a Resilient Built Environment Risk and Asset Management 2019, 1734 -1741.
AMA StyleLina Nunes, João Luís Parracha, Paulina Faria, Pedro Palma, António Maurício, Manuel Pereira. Towards an assessment tool of anobiid damage of pine timber structures. IABSE Symposium, Guimarães 2019: Towards a Resilient Built Environment Risk and Asset Management. 2019; ():1734-1741.
Chicago/Turabian StyleLina Nunes; João Luís Parracha; Paulina Faria; Pedro Palma; António Maurício; Manuel Pereira. 2019. "Towards an assessment tool of anobiid damage of pine timber structures." IABSE Symposium, Guimarães 2019: Towards a Resilient Built Environment Risk and Asset Management , no. : 1734-1741.